1. Field of the Invention
The present invention relates to nonwoven fabrics and, more particularly, to a nonwoven composite material which comprises a meltblown fabric layer of thermoplastic polymeric microfibers sandwiched between two prebonded reinforcing fabric layers of thermoplastic polymeric filaments, the three layers being continuously-bonded together to form a fabric material.
2. Description of the Prior Art
A wide range of nonwoven fabric laminates that incorporate meltblown materials are known. Such fabrics have been produced using a variety of lamination procedures.
U.S. Pat. No. 4,374,888 to Bornslaeger discloses a class of such laminates that are useful as recreational fabrics. U.S. Pat. No. 4,436,780 to Hotchkiss et al. discloses a meltblown-containing laminate for use as a wiper. U.S. Pat. No. 4,196,245 to Kitson et al. discloses a composite material having at least two meltblown fabric layers that is said to be useful as surgical gowns, surgical drapes, and the like. The Bornslaeger, Hotchkiss et al., and Kitson et al. fabrics are produced by point-bonding processes.
U.S. Pat. No. 4,041,203 to Brock et al. discloses a nonwoven fabric-like material that comprises a meltblown fabric and a web of substantially continuous and randomly deposited molecularly oriented filaments of a thermoplastic polymer. The web is not prebonded and thus has no integrity of its own until it is bonded to the meltblown fabric. The fabric and the web are point-bonded together to obtain a material that is said to have desirable strength characteristics and to possess a textile-like appearance, drape, and hand.
U.S. Pat. No. 3,795,571 to Prentice discloses a nonwoven fabric laminate comprising a meltblown microfiber mat that has high strip tensile strength, bonded to at least one other mat that has high tear resistance. The laminate can be formed by point-bonding or by adhesive bonding.
U.S. Pat. No. 4,508,113 to Malaney discloses five-ply disposable drapes that incorporate meltblown material. U.S. Pat. No. 4,555,811 to Shimalla discloses a nonwoven meltblown-containing laminate structure useful as an operating room gown. The Malaney and Shimalla laminates are made on a heated embossing calendar.